This invention relates to osteosynthesis plates, and more particularly to such plates useful to immobilize adjacent vertebral bodies.
Proper healing of injured or damaged skeletal parts requires immobilization of the injured skeletal segments to ensure the proper growth of new osseous tissue between the segments. Insufficient immobilization can compromise the healing process and may result in further complications or injury.
Osteosynthesis plates have been used to immobilize adjacent skeletal parts such as bones. Typically, a rigid plate is positioned to span bones or bone segments that must be immobilized with respect to one another. The plate is fastened to the bone, for example with bone screws, so that the plate remains in contact with the bone and that the bones or bone segments are immobilized.
Such plates have been used to immobilize a variety of bones, and have recently been adapted for use in fusing and immobilizing adjacent vertebral bodies. The morphology of spinal bone presents unique challenges to the design of effective osteosynthesis plates for fusing vertebral bodies. Among the challenges involved in fusing vertebral bodies is the effective installation of a plate that will resist migration despite the rotational and translational forces it faces. For a plate to work effectively in such an environment, screws must be properly positioned and anchored within the bone. Several known plate designs use elongate, slotted openings for screw placement in the plate. While useful in providing freedom of positioning screws, this contributes to the potential for slippage between the plate and screw head along the longitudinal axis of the plate. Such plates have also been designed to conform to the shape of vertebral bodies which they contact.
Despite the existence of osteosynthesis plate systems adapted for use in fusing vertebral bodies, there remains a need for an osteosynthesis plate system that is able to be securely installed between adjacent bones or bone segments, particularly vertebral bodies.
It is thus an object of the invention to provide an osteosynthesis plate system which maximizes immobilization of adjacent bones or bone segments. Another object is to provide such a system adapted for use in fusing adjacent vertebral bodies. A further object is to provide an osteosynthesis plate system for placement on the anterior surface of vertebral bodies to immobilize two or more adjacent vertebrae. It is also an object to provide an osteosynthesis plate system for placement on the posterior surface of vertebral bodies to immobilize two or more adjacent vertebrae. Another object is to provide such plate systems able to be more securely affixed to bone. Other objects will be apparent upon review of the disclosure that follows.